android-mediaplayer - android 媒体播放器连接状态与音频流链接(即 2%、4%...100% 然后在线广播开始播放)在 android

Question

当媒体播放器尝试在 android 中连接音频流链接(即 2%、4%...100% 然后在线广播开始播放)时，我如何获得缓冲状态。这是我的代码。

但我不知道如何解决我的问题。感谢提前提供任何帮助。

player.setOnBufferingUpdateListener(新的OnBufferingUpdateListener() {

            public void onBufferingUpdate(MediaPlayer mp, int percent) {
                playSeekBar.setSecondaryProgress(percent);
                Log.i("Buffering", "" + percent);
            }
        });

Answer 1

我解决了这个问题。链接在这里。 http://coderfriend.blogspot.com/

根据这里的要求，我分享博客内容..

当用户单击播放按钮播放广播时，我想显示连接状态(缓冲 1%、2%.. 99%)。当状态为 100% 时， radio 开始播放。我遇到了解决这个问题的问题。所以在这里我把这段代码分享给大家。

//首先创建这个类

public class StreamingMediaPlayer {

private static final int INTIAL_KB_BUFFER =  96*10/8;//assume 96kbps*10secs/8bits per byte

private TextView textStreamed;

private ImageButton playButton;

private ProgressBar    progressBar;

//  Track for display by progressBar
private long mediaLengthInKb, mediaLengthInSeconds;
private int totalKbRead = 0;

// Create Handler to call View updates on the main UI thread.
private final Handler handler = new Handler();

private MediaPlayer     mediaPlayer;

private File downloadingMediaFile;

private boolean isInterrupted;

private Context context;

private int counter = 0;

 public StreamingMediaPlayer(Context  context,TextView textStreamed, ImageButton    playButton, Button    streamButton,ProgressBar    progressBar)
 {
     this.context = context;
    this.textStreamed = textStreamed;
    this.playButton = playButton;
    this.progressBar = progressBar;
}

/** 
 * Progressivly download the media to a temporary location and update the MediaPlayer as new content becomes available.
 */ 
public void startStreaming(final String mediaUrl, long    mediaLengthInKb, long    mediaLengthInSeconds) throws IOException {

    this.mediaLengthInKb = mediaLengthInKb;
    this.mediaLengthInSeconds = mediaLengthInSeconds;

    Runnable r = new Runnable() {  
        public void run() {  
            try {  
                downloadAudioIncrement(mediaUrl);
            } catch (IOException e) {
                Log.e(getClass().getName(), "Unable to initialize the MediaPlayer for fileUrl=" + mediaUrl, e);
                return;
            }  
        }  
    };  
    new Thread(r).start();
}

/** 
 * Download the url stream to a temporary location and then call the setDataSource 
 * for that local file
 */ 
public void downloadAudioIncrement(String mediaUrl) throws IOException {

    URLConnection cn = new URL(mediaUrl).openConnection();  
    cn.connect();  
    InputStream stream = cn.getInputStream();
    if (stream == null) {
        Log.e(getClass().getName(), "Unable to create InputStream for mediaUrl:" + mediaUrl);
    }

    downloadingMediaFile = new File(context.getCacheDir(),"downloadingMedia.dat");
    if (downloadingMediaFile.exists()) {
        downloadingMediaFile.delete();
    }

    FileOutputStream out = new FileOutputStream(downloadingMediaFile);  
    byte buf[] = new byte[16384];
    int totalBytesRead = 0, incrementalBytesRead = 0;
    do {
        int numread = stream.read(buf);  
        if (numread <= 0)  
            break;  
        out.write(buf, 0, numread);
        totalBytesRead += numread;
        incrementalBytesRead += numread;
        totalKbRead = totalBytesRead/1000;

        testMediaBuffer();
           fireDataLoadUpdate();
    } while (validateNotInterrupted());  
           stream.close();
    if (validateNotInterrupted()) {
           fireDataFullyLoaded();
    }
} 

private boolean validateNotInterrupted() {
    if (isInterrupted) {
        if (mediaPlayer != null) {
            mediaPlayer.pause();
            //mediaPlayer.release();
        }
        return false;
    } else {
        return true;
    }
}


/**
 * Test whether we need to transfer buffered data to the MediaPlayer.
 * Interacting with MediaPlayer on non-main UI thread can causes crashes to so perform this using a Handler.
 */ 
private void  testMediaBuffer() {
    Runnable updater = new Runnable() {
        public void run() {
            if (mediaPlayer == null) {
                //  Only create the MediaPlayer once we have the minimum buffered data
                if ( totalKbRead >= INTIAL_KB_BUFFER) {
                    try {
                        startMediaPlayer();
                    } catch (Exception e) {
                        Log.e(getClass().getName(), "Error copying buffered conent.", e);               
                    }
                }
            } else if ( mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000 ){
                //  NOTE:  The media player has stopped at the end so transfer any existing buffered data
                //  We test for < 1second of data because the media player can stop when there is still
                //  a few milliseconds of data left to play
                transferBufferToMediaPlayer();
            }
        }
    };
    handler.post(updater);
}

private void startMediaPlayer() {
    try {  
        File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");

        // We double buffer the data to avoid potential read/write errors that could happen if the
        // download thread attempted to write at the same time the MediaPlayer was trying to read.
        // For example, we can't guarantee that the MediaPlayer won't open a file for playing and leave it locked while
        // the media is playing.  This would permanently deadlock the file download.  To avoid such a deadloack,
        // we move the currently loaded data to a temporary buffer file that we start playing while the remaining
        // data downloads. 
        moveFile(downloadingMediaFile,bufferedFile);

        Log.e(getClass().getName(),"Buffered File path: " + bufferedFile.getAbsolutePath());
        Log.e(getClass().getName(),"Buffered File length: " + bufferedFile.length()+"");

        mediaPlayer = createMediaPlayer(bufferedFile);

        // We have pre-loaded enough content and started the MediaPlayer so update the buttons & progress meters.
        mediaPlayer.start();
        startPlayProgressUpdater();           
        playButton.setEnabled(true);
    } catch (IOException e) {
        Log.e(getClass().getName(), "Error initializing the MediaPlayer.", e);
        return;
    }  
}

private MediaPlayer createMediaPlayer(File mediaFile)
throws IOException {
    MediaPlayer mPlayer = new MediaPlayer();
    mPlayer.setOnErrorListener(
            new MediaPlayer.OnErrorListener() {
                public boolean onError(MediaPlayer mp, int what, int extra) {
                    Log.e(getClass().getName(), "Error in MediaPlayer: (" + what +") with extra (" +extra +")" );
                    return false;
                }
            });

    //  It appears that for security/permission reasons, it is better to pass a FileDescriptor rather than a direct path to the File.
    //  Also I have seen errors such as "PVMFErrNotSupported" and "Prepare failed.: status=0x1" if a file path String is passed to
    //  setDataSource().  So unless otherwise noted, we use a FileDescriptor here.
    FileInputStream fis = new FileInputStream(mediaFile);
    mPlayer.setDataSource(fis.getFD());
    mPlayer.prepare();
    return mPlayer;
}

/**
 * Transfer buffered data to the MediaPlayer.
 * NOTE: Interacting with a MediaPlayer on a non-main UI thread can cause thread-lock and crashes so
 * this method should always be called using a Handler.
 */ 
private void transferBufferToMediaPlayer() {
    try {
        // First determine if we need to restart the player after transferring data...e.g. perhaps the user pressed pause
        boolean wasPlaying = mediaPlayer.isPlaying();
        int curPosition = mediaPlayer.getCurrentPosition();

        // Copy the currently downloaded content to a new buffered File.  Store the old File for deleting later.
        File oldBufferedFile = new File(context.getCacheDir(),"playingMedia" + counter + ".dat");
        File bufferedFile = new File(context.getCacheDir(),"playingMedia" + (counter++) + ".dat");

        //  This may be the last buffered File so ask that it be delete on exit.  If it's already deleted, then this won't mean anything.  If you want to
        // keep and track fully downloaded files for later use, write caching code and please send me a copy.
        bufferedFile.delete();  
        moveFile(downloadingMediaFile,bufferedFile);

        // Pause the current player now as we are about to create and start a new one.  So far (Android v1.5),
        // this always happens so quickly that the user never realized we've stopped the player and started a new one
        mediaPlayer.pause();

        // Create a new MediaPlayer rather than try to re-prepare the prior one.
        mediaPlayer = createMediaPlayer(bufferedFile);
        mediaPlayer.seekTo(curPosition);

        //  Restart if at end of prior buffered content or mediaPlayer was previously playing. 
        //    NOTE:  We test for < 1second of data because the media player can stop when there is still
        //  a few milliseconds of data left to play
        boolean atEndOfFile = mediaPlayer.getDuration() - mediaPlayer.getCurrentPosition() <= 1000;
        if (wasPlaying || atEndOfFile){
            mediaPlayer.start();
        }

        // Lastly delete the previously playing buffered File as it's no longer needed.
        oldBufferedFile.delete();


    }catch (Exception e) {
        Log.e(getClass().getName(), "Error updating to newly loaded content.", e);                   
    }
}

private void fireDataLoadUpdate() {
    Runnable updater = new Runnable() {
        public void run() {
            if((totalKbRead>19)&&(totalKbRead<120))
                textStreamed.setText((totalKbRead-19 + "% Buffering"));//show buffering status.. ie 1%,2%. in ui
            else if(totalKbRead<19)
                textStreamed.setText(("Connecting..."));
            else
            textStreamed.setText((""));

            float loadProgress = ((float)totalKbRead/(float)mediaLengthInKb);
            progressBar.setSecondaryProgress((int)(loadProgress*100));
        }
    };
    handler.post(updater);
}

private void fireDataFullyLoaded() {
    Runnable updater = new Runnable() {
        public void run() {
               transferBufferToMediaPlayer();

               // Delete the downloaded File as it's now been transferred to the currently playing buffer file.
               downloadingMediaFile.delete();
            textStreamed.setText(("Audio full loaded: " + totalKbRead + " Kb read"));
        }
    };
    handler.post(updater);
}

public MediaPlayer getMediaPlayer() {
    return mediaPlayer;
}

public void startPlayProgressUpdater() {
    float progress = (((float)mediaPlayer.getCurrentPosition()/1000)/mediaLengthInSeconds);
    progressBar.setProgress((int)(progress*100));

    if (mediaPlayer.isPlaying()) {
        Runnable notification = new Runnable() {
            public void run() {
                startPlayProgressUpdater();
            }
        };
        handler.postDelayed(notification,1000);
    }
}   

public void interrupt() {
    playButton.setEnabled(false);
    isInterrupted = true;
    validateNotInterrupted();
}

/**
 *  Move the file in oldLocation to newLocation.
 */
public void moveFile(File    oldLocation, File    newLocation)
throws IOException {

    if ( oldLocation.exists( )) {
        BufferedInputStream  reader = new BufferedInputStream( new FileInputStream(oldLocation) );
        BufferedOutputStream  writer = new BufferedOutputStream( new FileOutputStream(newLocation, false));
        try {
            byte[]  buff = new byte[8192];
            int numChars;
            while ( (numChars = reader.read(  buff, 0, buff.length ) ) != -1) {
                writer.write( buff, 0, numChars );
              }
        } catch( IOException ex ) {
            throw new IOException("IOException when transferring " + oldLocation.getPath() + " to " + newLocation.getPath());
        } finally {
            try {
                if ( reader != null ){                       
                    writer.close();
                    reader.close();
                }
            } catch( IOException ex ){
                Log.e(getClass().getName(),"Error closing files when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
            }
        }
    } else {
        throw new IOException("Old location does not exist when transferring " + oldLocation.getPath() + " to " + newLocation.getPath() );
    }
}

//现在将下面的代码复制到activity中

StreamingMediaPlayer audioStreamer = 
new  StreamingMediaPlayer(this,textStreamed,playButton,
streamButton,progressBar);
audioStreamer.startStreaming("your streaming station name",5208, 216);

我认为这对你有帮助:)